Activities enhancing human intellectual creativity increases human evolution. In this respect, desks played a fundamental part in promoting such activities. FIG. 1 is a side view showing an exemplary use of a conventional desk. As shown in FIG. 1, a convention desk 10 includes a horizontal panel 11 and support legs 12. Since the horizontal panel 11 is fixed to the support legs 12, the user's upper body must bow down to read books or papers placed on the horizontal panel 11. In such a case, this causes incorrect posture that leads to pain in the neck, shoulder, waist, etc. In particular, a user who has to sit for a long time would have to often endure such pains. For example, if the head is bent down for a long time, then the neck bone turns into an “I” shape to support the bent neck bone and the muscles surrounding the neck bone become tense. This obviously causes pain in the neck and shoulder and further leads to cervical disk problem.
To resolve the aforementioned disadvantages of the conventional desk, various types of desks have been developed. For example, FIG. 2 shows an exemplary use of a study desk disclosed in Korean Utility Model Registration No. 20-0182180. As shown in FIG. 2, the study desk 20 has a horizontal panel 21 and support legs 22. The horizontal panel 21 is configured to rotate around a rotation shaft 21a with respect to the support legs 22, thus adjusting the slant angle of the horizontal panel 21. However, the mere adjustment of the slant angle of the horizontal panel 21 only merely eases the bent degree of the user's upper body. Accordingly, the upper body of the user must still bow down to use the desk.